LIBRARY OF CONGRESS. 



§^tp t ©ajiijn$Ijt If xu 

Shelf.. 

UNITED STATES OF AMERICA. 



SAWS; 



HOW TO 



Straighten and Gum 



ALL KINDS. 



BY 



A. K. WILBUR, 



ONEONTA, N. Y. 



Colegrove, Job Printer, 
oneonta, n. y. 






TS'SSI 

,\V5 



ENTERED ACCORDING TO ACT OF CONGRESS IN THE YEAR 1888, 

BY A. E. WILBUR, 

IN THE OFFICE OF THE LIBRARIAN OF CONGRESS AT WASHINGTON. 



5 I* 



$< 



1 



I 



i 



INSTRUCTIONS 



is^ ON 






Straightening and taming Saws, 

Owing to a universal want among mill-men for 
a plain, practical and comprehensive treatise on 
the art of straightening saws, the author has, in 
the following pages, endeavored to set forth the 
general principles by illustration so that any me- 
chanic of ordinary ability can by diligent practice 
do that class of work which needs to be done in 
mills using circular and other kinds of saws. 



SAWS. 

Many attempts have been made to give the users 
of saws full directions by which they can do their 
own smithing, but many of them have fallen far 
short of what they intended to accomplish. 
Although the author of the following pages does 
not claim that a k ' green ' ' man can take up this 
particular trade, and by the aid only of these pages 
get to be an expert in a very short time ; he does 
claim that by close application of principles 
herein shown, he can quickly be enabled to do 
good and practical work. All experienced mill- 
men will allow that if they could properly ham- 
mer their own saws it would not unfrequently 
happen that they could effect a great saving in 
time and expense by doing this class of work 
themselves. 

The mill-owner's best friend is a true working 
saw. If he has good machinery and good, prac- 
tical men to operate and keep in order he will 
find that the quality of his work will soon have 
favor in the lumber market where competition is 
very strong and good work favored at the present 
time. 

The gumming of saws is often entrusted to in- 
experienced men who, by their inability to prop- 
erly do the work, cause the plate to become out 
of true and unlit for practical use until further 
repairs are made upon it which oftentimes cause 
much unnecessarv delay and loss of time that 



SAWS. 5 

might be obviated had the operator had proper 
instructions placed before him. To chamber the 
teeth upon a good and true plate without effecting 
its tension is a feat that requires much knowledge 
on the part of the operator as to the effect given 
the plate by the action of the cutter or gimiraer. 
The writer in the following pages has striven to 
give sawyers and other mechanics, to whom this 
class of work may come, full and plain instruc- 
tions in this branch of saw repairing, and if the 
rules and principles herein given be well followed, 
the result will be highly satisfactory. 



The sawyer to operate successfully a circular 
saw must observe the following points : The 
plate should have a tension adapted to the speed 
applied ; it must be free from Haws, blisters and 
kinks ; its teeth must have sufficient room to 
carry the dust from the kerf ; it must be tiled 
and swaged properly ; it must have the teeth 
formed so as not to k ' heel ' ' when in the cut ; its 
width of kerf must be governed by the condition 
and kind of timber to be sawn ; it must be per- 
fectly round and in balance ; its mandrel must 
run cool and have a slight end play ; it must be 
in line with the carriage and stand perfectly 
plumb and at right angles to the bed of its head- 



6 SAWS. 

blocks ; it must not be crowded between the 
guides ; it must not have a feed stronger than 
it can work under ; it must have power enough 
applied to maintain an equal speed the whole 
length of cut ; it must be favored in large knots 
and in timber that has a tendency to spring and 
bind the plate. 

Although the log band saw is coming largely 
into use it will not, on account of its large expense, 
more difficult management and slowness of feed, 
displace but comparatively few of the many 
hundreds of circular log mills now in use. Owing 
to the great improvements of late years in the 
manufacture of saws their quality has largely 
been improved while their cost has been some- 
what reduced by many factories of this country. 
Natural gas for heating, pressure disks used in 
tempering, and improved machinery for grinding 
and polishing are among the most important im- 
provements now adapted. 

The purchaser of a new saw should exercise 
much care in his selection as there are on the mar- 
ket goods of this class varying in quantity like 
other wares manufactured and sold. Usually a 
trial of thirty days in actual use is .the best test 
of truth in all form of saw plates. 



SAWS. 



®eg@rif\\®¥i ©f fSooIg. 



STRAIGHT-EDGES. 

To straighten a saw of any kind but few tools 
are needed. By referring to Fig. 1, you will iind 
illustrated three sizes of steel straight-edges that 
are used in doing work of this class, as well as in 
factories and general repair shops. The largest 
size is forty-eight inches long, three inches wide, 
seven gauges thick, tapered at the ends and planed 
on both edges. This size is nsed principally in 
tensioning saws on their mandrels with burr 
tightened and guides in place. It is also a very 
handy tool about the mill for leveling frames, 
plumbing uprights, straightening shafting, etc. 

The medium size is twenty-four inches long, 
two inches wide, about twelve gauges thick, and 
planed on both edges. 

The smallest size is twelve inches long, one and 
one-half inches wide, tapered and planed in the 
same manner. These sizes are used on all kinds 
of circulars, band, mill, cross-cut, drag and gang 
saws. 




SAWS. 



ammerg. 



For ordinary tensioning, the common pene 
hammer, shown in Pig. 2 at B, is principally 
used. This hammer, as well as all of the rest, 
should be made of good tool steel. The pene 
hammer should weigh about 2& pounds, and have 
its corners and face quite well rounded. At C 
is shown the form of a dog-head hammer which 
has a weight of 3£ pounds. It is rounded con- 
siderably on the face, and has its handle set at an 
angle of 80° to the head. The use of this ham- 
mer is for stretching unequal places in plates, 
as its blow is a dead om, being delivered in a 
direct line. At D is shown a blocking hammer 
weighing about live pounds. This hammer is 
made with two faces, one on each end and at 
opposite angles. The faces are at an angle of 95° 
to the handle. Thus you will see that the opera- 
tor can by striking a blow with each end deliver 
them at right angles without moving the plate or 
changing his position, and forming by striking- 
one blow over the other a perpendicular cross. 
Referring to E. , another form of blocking hammers 
is illustrated. This is made the same as the other 
with the excei)tion that one face is parallel with 
the handle and the other at right angles. This 
hammer when used will, on reversing ends, form 
by its marks on the plate an oblique cross. By 
the use of these different hammers the smith can 
deliver just such a blow as lie pleases without 
moving his plate upon the anvil. 



10 SAWS. 

Qnuifg. 



For ordinary mill work the anvil represented 
at A, Fig. 3, is usually sufficient. This anvil is 
made of hard cast iron eight inches in diameter, 
octagon in shape, and about two and one-fourth 
inches in thickness. It is planed perfectly fiat on 
one side and turned about one-sixteenth oval on 
the other. In tensioning the larger sizes of circu- 
lar saws, they are commonly left upon the man- 
drel, and the hand-anvil held by one hand on the 
opposite side of the plate from which the opera- 
tor intends to deliver his blows. 

At B is shown an ordinary saw-maker"' s anvil 
used in all saw factories and general repair shops. 
This anvil is made in the form represented with a 
cast-iron body and a heavy cast-steel face, nicely 
rounded and polished. Its weight is from one 
hundred and fifty to two hundred pounds. It 
should be mounted upon the upper end of an 
upright post running down tli rough the floor and 
bedded in the ground with a large stone beneath 
it. By being thus arranged there is very little 
spring or re-bound to blows delivered upon the 
plates lying on the anvil, providing they lay flat 
upon the face. 



12 saws. 

§iffe.@tg ©f tfie Ifcaoimer. 



Before the smith delivers a blow upon his plate 
he should know how that blow is going to effect 
the plate in the locality of its delivery. If he 
goes at it in any other than a systematic method 
he will soon find that he is not straightening, but 
distorting and warping from any and all degrees 
of trueness. A blow delivered by the round- 
faced pene or dog-head hammer in a perpendicu- 
lar line will effect as shown in plate A at N. Its 
effect being equal on all sides at the point of con- 
tact. The same effect takes place by a perpen- 
dicular blow as shown at A with the blocking 
hammer, excepting that which is changed by the 
form of the hammer itself. At R and S the effect 
is very much different. This represents a blow 
falling on a slant, thus producing more expan- 
sion beyond the point of contact and in direct 
line of hammer stroke. In delivering blows upon 
a saw the smith must pay particular attention to 
the manner in which he delivers them. Unless 
the nature of his work requires a slanting blow 
it is always best to hammer in a perpendicular 
and direct line. Referring to B, Fig. 4, the effect 
of many blows delivered by a round-faced ham- 
mer on the central portion of a plate is to expand 
that section, and to accommodate this expansion 
the plate must dish. It is now out of true and 
to equalize again to its original tension the section 
at C must be expanded in order to take up the 
slack at B. The operator should bear in mind 



14 SAWS. 

;ffe@ts ©f tfie jammer. 



that in doing this he must reverse the plate, and 
do equally as much hammering on either side, 
otherwise the surface of one side will receive more 
strain than the other ; consequently a true plate 
cannot be obtained until both are equally ex- 
panded. The plate shown at A, Fig. 5, has repre- 
sented each end bent or sprung from a true line. 
In order to again straighten the smith should 
use the blocking hammer and deliver blows as 
shown on the plate B. The expansion from these 
blows is nearly all in the line indicated by the 
arrows shown upon the plate. Referring to plate 
A, Fig. 4, at S one can readily comprehend why 
the plate under treatment will soon assume its 
original form. By delivering the blows from the 
blocking hammer on the convex side the expan- 
sion takes place on the contracted parts of the 
plate and thus throws it again back gradually in 
a straight line. The operator must bear in mind 
that any and all of these principles and methods 
are applicable to saw plates under treatment. In 
hammering a plate the operator must use great 
care and judgment in regard to heft of blows 
delivered. The quality of steel, different de- 
grees of temper, thickness and size of plates, 
have all to be taken into consideration. For in- 
stance, the smith is hammering a sixteen or twen- 
ty gauge saw, he must not use as heavy and 
strong blows as if he were hammering a rive 
gauge large circular. 



16 SAWS. 

\ound, 




A circular saw constantly heated and cooled 
about the center will soon expand permanently in 
that locality in such a degree as to cause the 
plate to become loose, or in other words, out of 
tension. Referring to Fig. 6, the plate A, 
represents a rim-bound saw. At B and C is 
shown how the plate stands off from the straight 
edge when stood upon one side. A saw in this 
condition cannot work well as the looseness of the 
plate will not allow of any but a very slow feed. 
If the saw be run at a high rate of speed a por- 
tion of this slack will be equalized by the expan- 
sion due to the speed itself. If the saw be run at 
;i slow rate of speed it should have a tension that 
will cause the plate to be quite stiff and rigid. In 
order to equalize the tension on a rim-bound saw, 
lay it out by marking across the plate with a 
piece of chalk from D to E and from L to Gr, then 
on the opposite side midway between the others, 
from H to I and from J to K. If the operator 
wishes to use the hand anvil, leave the saw upon 
the mandrel with burr tightened and guides 
loosened. Commencing at the center hold the 
anvil on one side while delivering blows, at first 
very light and increasing in heft and force as he 
approaches the rim. (See represented upon lines 
drawn across the plate, Fig. 6.) After going over 
the saw in this manner on all the lines, care being- 
taken not to hammer too much on the concave 
side, try the plate with the straight edge and if 
not effected sufficiently draw another set of lines 
in the same manner between those previously 
drawn and proceed as before until the rim is suffi- 
ciently stretched or expanded. 



18 SAWS 

aa5 ©eater §om 



Usually when a sawyer attempts to run a cen- 
ter-bound saw successfully lie finds the trial a 
complete failure. A saw in this condition cannot 
be run with any degree of accuracy. It is seldom 
a solid toothed saw will get in this condition 
unless it is roughly used while gumming or has 
been unduly heated at the outer rim. One of the 
greatest difficulties in running an inserted toothed 
saw is due to the expansion given the outer edge 
of the plate by the teeth being sprung or riveted 
in their sockets. Unless this expansion be nicely 
adjusted the plate will become center bound, 
and consequently cannot cut in a straight line. 
By referring to Fig. 7, at A, is shown a plate that 
is center bound and one can easily see the form it 
assumes. In order to correct this, lay the saw 
out, as shown on plate B, with a piece of elm Ik. 
drawing a set of lines as explained on plate A, 
Fig. 6. Next place the saw upon the anvil, or if 
the operator choose to use the hand anvil, leave 
the saw upon the mandrel holding the anvil in 
the left hand. Proceed by commencing at* the 
outer rim hammering towards the center, veiy 
light blows at first and gradually increasing the 
heft and force as shown by hammer marks on the 
plate. Go over the set of lines drawn on one side 
and then reversing go over the other in a like 
manner. If you have not the desired tension by 
going over in this manner on both ^ides then 
draw a new set of lines between tin se previously 
drawn and proceed in this way until the desired 
tension is obtained. Care should be taken not to 
over expand the center, causing the ] late to be- 
come rim bound. 



20 SAWS. 



am IB fi stored. 



This is a common term applied especially to 
large circular saws that have been accidentally, 
carelessly or otherwise over-heated and bulged in 
different places upon the plate. It is evident 
that a saw in this condition cannot be depended 
upon for accurate work. The prominent parts of* 
the plate will when passing continuously through 
the cut come in contact with the side of the kerf, 
thus expanding more and more by the friction 
and heat. To remove these loose places the plate 
must be expanded by the hammer in a locality 
that will take up and equalize the tension again. 
By referring to Fig. 8, at B. plate A, you will see 
represented one of these blisters, and in order to 
effectually remove it, lay out the plate as showed 
by the lines from D to E and P to G on both sides 
and hammer with the blocking hammer as shown, 
care being taken not to hammer more on one side 
than the other. This being done deliver a few 
blows with the round faced hammer upon the 
convex side of the blister. After trial if it be 
not all removed repeat the operation until the 
tension be again equalized. 



22 saws. 

©insofar $<nm K'im&ed. 



A circular saw bent or kinked is represented 
in Fig, 9, at A and B. Oftentimes through 
accident a plate will get bent, sprung or kink- 
ed and, as a result, must be straightened be- 
fore its use can be continued. In order to reme- 
dy this, lay out the plate on the convex side as 
represented by lines 0, D, and E F on plate B. 
The plate is now hammered on the same principle 
as shown in Fig. 5, plate A, excepting that the 
form must be largely taken into consideration. 
On the one a circular plate and on the other a 
square ; but the general principle involved being 
the same. Hammer as shown on the lines (J, I), 
with the blocking hammer in order to pull the 
the plate back in line again through the expan- 
sion given the underside. By doing this a 
certain amount of expansion is exerted upon the 
plate cross-wise and must therefore be equalled 
by a certain amount given as shown upon the 
lines E, F. The straight edge should be fre- 
quently applied to denote when the required 
amount be iriven. 



24 saws. 




This class of saws, owing to their longitudinal 
shape or form, and having a reciprocating motion, 
are usually subjected to hard usage and very fre- 
quently become warped, kinked or bent. At A, 
Fig. 10, is represented a long saw having a twist 
running obliquely across the plate. In order to 
correct this, lay the saw upon the anvil with 
drooping corner downward and hammer as shown 
on plate B; when this section be sufficiently 
raised change ends, reverse sides with the plate, 
and proceed as before. In tensioning saws that 
are strained, such as gang, mully, frame and 
band saws, care should be taken to have the ten- 
sion well equalized, thus avoiding any looseness 
in the plate while at work. If the operator be a 
new beginner in the art of saw hammering, it 
would be a good plan for him to commence by 
practicing a short time on a steel or sheet iron 
plate procured for the purpose. He can thus 
readily see how his blows effect the plate and 
will gradually find that he can control its tension 
wholly with his hammer ; then by slowly trying 
the saw plates he will soon find them quite easily 
mastered. 



26 saws. 

— s- 

Too much rare cannot be exercised in doing 
this class of saw repairing, as there are more saws 
crippled by bad gumming than the actual work 
performed by them. For cutting out or removing 
the surplus metal from the teeth many kinds and 
forms of tools have been devised. Although 
there are a few good and effectual methods of 
doing this work, there are many that are decided- 
ly objectionable and ruinous to the plates. Some 
of the best methods used are the stone, emery, 
and burr gummers. To properly gum a large 
circular saw with an emery wheel suspend the 
plate from the center as shown in Fig. 11 at B 
and C, and support it by a rest built up so as to 
place the saw in a direct line with the center of 
mandrel that holds and drives the wheel E. A 
saw held in this manner allows the wheel to cut 
square across the plate and thus avoids all ten- 
dency to chatter and bound, leaving the seat 
square and forming a good chamber for dust, 
The author has used many different makes of 
wheels, and while some cut slow and heat fast, 
there are others that cut fast and heat slow ; 
among the latter class a celluloid wheel, by the 
author's experience, does the work in the best 
and most satisfactosy manner. In gumming, the 
operator should press the plate quite firmly against 
the wheel for four or five seconds, and then with- 
drawing pass on to the next tooth, and in this 
manner passing around the saw several times be- 
fore completing. 



28 saws. 



A true plate out of balance cannot run steadily 
even though its tension be well equalized. By 
referring to Fig. 12, at B, is is shown a template 
or gauge which if used when laying out the plate 
for gumming, will keep the saw in good running 
balance. The gauge is made in two sections, as 
shown at C, held together by two binding screws, 
F and Gr, which allows taking up as the saw 
wears smaller. At B is shown the general form 
of the gauge ; the lower end is fitted to the cen- 
ter or eye of the saw and upon the upper end is 
formed the desired shape of tooth. Placing the 
point D at the point of the lowest tooth upon the 
plate, mark with a sharp steel point around the 
form E, as shown at H. Allow the cutter, of 
whatever form it may be, to displace evenly the 
metal along the lines. When the saw has been 
dressed and Hied it will be perfectly round and 
will run well balanced. Long saws may be laid 
out and gummed upon the same principle, except 
that the gauge must be made to work wholly 
from the points of the teeth, there being no cen- 
ter or parallel back to move the gauge from. 



30 SAWS. 



Dtome (Summer. 



A very cheap and effectual glimmer may be 
made from a common grind stone in the follow- 
ing manner: Procure a stone about twenty-eight 
inches in diameter, \\ inches thick, of medium 
grit and perfectly free from seams, flaws and 
breaks. Dress it flat with a chisel around the 
eye in the locality where the mandrel collars 
come in contact, and cut a groove from center 
back, clearing the collar to pour the metal 
through. Place the stone upon the mandrel 
with a thin hard wood collar in place of loose one, 
as this with the thickness of the stone will allow 
the burr to be tightened, holding the stone in 
position. When all are in place with stone cen- 
tered as nearly as possible, pack around the 
collars putty enough to All all crevices, and build 
at the end of groove a tunnel, as shown in Fig. 
13, at X). Melt a quantity of lead sufficient to 
till the vacancy ; pour into the tunnel and allow 
it to cool. The stone is now ready to be turned 
into proper shape for gumming. Build a rest 
about the stone as shown at C ; allow the stone 
to revolve at about 125 revolutions per minute, 
and with a piece of round iron or gas pipe turn 
off as shown at A and B. The operator should 
not bear on too hard or allow his tool to catch, as 
there might be danger of fracturing the stone. 
It is always best in using a stone or emery wheel 
not to stand directly in front of it, as it is not 
necessary and in case of breakage pieces almost 
invariably fly in a direct line with wheel. With 
due care and proper treatment however, accidents 
of this kind seldom if ever occur. 



32 saws. 

(piammiE>< 



The rapidity with which this form of glimmer 
will cut into steel plate is suprising. By referring 
to Fig. 14, the general arrangement for gumming 
a circular saw is shown. The plate is suspended 
by the center as with the emery wheel, the edge 
resting upon the support D, a tub of water is 
placed as shown at C, with faucet and tube con- 
nected, directing a stream upon the stone and 
plate at the point of contact, thus facilitating the 
rutting action and keeping the metal cool. The 
stone should be run at about 275 revolutions per 
minute, and be covered by a wooden or sheet 
metal covering to prevent water from flying upon 
the operator while at work. To secure the best 
results, the rest supporting the saw should be 
lowered about one inch below the center of the 
stone, thus cutting a very little obliquely across 
the plate. The writer has with this form of 
gummer gummed a large circular saw, cutting 
out from each tooth about three-fourths of an 
inch in depth of metal, in less than thirty min- 
utes without injury to the plate. In using this 
form of gummer care must be taken not to run 
at an overrate of speed, as the centrifugal force is 
liable to burst the stone and do much damage. A 
good burr gummer may be used without injury to 
a plate if the operator chooses to be at the extra 
expense, apply his muscle, and follow well the 
the directions given with the machine. Press 
glimmers should be used only in saw factories. 



34 saws. 

»e:etfi UJelT ©fiambered. 



It is not economy for a sawyer to use a saw 
without gumming until the throat or sawdust 
chamber be filled as shown in Fig. 15, at B, plate 
A. It is obvious that a plate with teeth in this 
condition cannot stand up under heavy feed, as 
the sawdust by more than filling its space will 
crowd itself out at the sides, consume a large 
amount of power, cause the plate to heat and, as 
a consequence a poorly sawed lot of lumber will 
be produced. By frequently gumming and keep- 
ing the form of teeth as shown on lines F and C, 
the liability of stretching the plate upon the rim 
by cutting out a large amont of metal at one 
gumming is avoided. Teeth in this form are 
very easily dressed, as the iile has free action by 
not coming in contact with any of its corners. 
By producing, with the file, press glimmer, or 
any other device, square corners at the base of 
teeth, there is danger of the plate eventually 
cracking, as shown at E. Band saws should be 
hied or gummed on a circle at the base of their 
teeth, as the action over wheels tends to bend and 
crack them in that locality. 



36 saws. 



l^epeurmg §roK©Fi (Seetfi. 



Till ess the operator understands well the art of 
brazing steel, he should repair a broken tooth by 
inserting a removable point or tooth accordingly 
as the shape and circumstances will allow. If 
broken, as shown on the plate A, Fig. 16, at line 
B, the spike tooth, as shown at C, is a very good 
way of repairing the break. As the saw becomes 
smaller the inserted tooth will soon wear back to 
the point at D, and then by removing the stub 
and gumming out the metal on the line E, a new 
and perfect tooth is again formed. To insert a 
tooth of this form, cut the metal out within three- 
thirty-seconds of an inch from the lines around 
the tooth C. File the edge as shown at F in a V 
shape. Form the tooth, C, the desirable size and 
cut a groove around it as shown at G ; slide it 
into place, care being taken not to have it fit too 
tightly, drill two small holes at H, H, and insert- 
two rivets, countersinking and upsetting them 
below the surface of the plate. All breaks will 
not be of the form shown, hence a tooth must be 
formed and inserted that will be best suited for 
the occasion. Solid toothed saws may in this 
way be - converted into removable or inserted 
toothed ones in the same manner by placing the 
needed tension upon the plate after the teeth 
are in place. 



38 saws. 



Repairing a f^raetMredt Plate. 



If by accident or otherwise a plate becomes 
fractured at the outer rim extending inward, the 
break, if not too deep, may be effectually re- 
paired as follows : Trace the fracture to the ex- 
treme end and drill a small hole through the 
plate at that point to prevent it from going- 
deeper or extending farther. Lay out the plate 

A, Fig. 17, as shown at C, D, across the break 

B. Drill two f inch holes through the plate and 
countersink them from both sides, thus forming 
a V about the rim of both sides. Cut out the 
space I, with an emery wheel or file, leaving the 
sides square. Form from a, plate of wrought 
iron about two gaiiges thicker than the saw a 
a dovetail in form as shown at E, that will fill the 
socket, giving it a slight draw endwise and after 
heading down put it upon a stone or emery wheel 
and reduce the thickness to that of the plate. 
This, if properly done, is a very satisfactory way 
to repair a fracture of this kind. If a circular 
plate be cracked near the eye or midway, it should 
be discarded, as it is unsafe for further use. 



40 SAWS. 



fBr^iFig gand |>@ajg. 



At A, Fig. 18, is shown a very convenient form 
of clamp to be used in brazing band saws. The 
plate, if it be a large one, should have its ends 
beveled at least 1J inches back and be placed in 
the clamp so as to form the thickness of the plate 
at the joint after it is brazed. Feed a small 
quantity of muriatic acid all the small pieces of 
zinc it will consume, and dilute with the same 
quantity of soft water. Place a thin strip of 
silver solder between the ends and cover all with 
the flux. Heat to a bright cherry red a large pair 
of tongs with jaws long enough to reach across the 
width of the plate. Remove all scale and clamp 
the lap between the jaws and have a helper clasp 
the farther ends with another pair and squeeze 
tightly until the plate be sufficiently heat ; then 
gradually pull off the hot tongs, following up 
with another pair slightly warmed. When cooled, 
if properly done, the splice will have a temper 
equal to that of the plate. File off all surplus 
solder, smooth off the lap and the plate is ready 
for use. 



42 saws. 

^ru\n<g Tslp ©offers. 

— % 

Many good saws are condemned simply from 
the want of truth in the mandrel. A mandrel, 
although perfect when new, will sometimes be- 
come imperfect and out of true by constant use. 
Frequently heating the bearing next to the fast 
collar will almost invariably cause the collars to 
become out of true, and if the saw and mandrel 
be subjected to hard strain the collars will be 
more or less effected. It takes but a slight va- 
riation at the center of a large circular saw to 
cause a considerable at the rim. Oftentimes 
these defects in the mandrel which cause unfaith- 
fulness on the part of the saw is misleading, and 
many times the sawyer is puzzled to know what 
to do next as he has vented all of his skill upon 
the saw, thinking the fault lay with it. The 
collars may be effectually tested in the following 
manner : Form a steel turning tool as shown in 
Fig. 19, at T) ; give it a temper of light gold color 
and insert it into a wooden handle as shown at B. 
Leave the mandrel in its bearings and build up a 
solid rest under the fast collar as shown at C. 
Have a helper turn the mandrel slowly with the 
belt removed, while with the tool held firmly in 
the hands the operator may remove any variation 
upon the collar. If this be done carefully, pro- 
viding the mandrel runs accurately in its bearings 
the collars will be again in good condition for 
use. The fast collar should have a bearing of 
about one-half inch at the rim with the center 
around the stud, hollowed out about one-thirty- 
second of an inch. The loose collar should be 
dressed perfectly fiat upon its face and with the 
plate between will conform itself accurately with 
the other when the burr is tightened. 




mm 

riMHMBHPl 



SAWS. 

s 

All large circular saws should be fitted upon 
their mandrels with two lug or stay pins to pre- 
vent the plate from slipping between the collars. 
If they are not fitted in this way when placed in 
the mill, or by accident are cut off, they may be 
drilled and fitted as follows : Build a rest as 
shown at P, Fig. 20, place the lower end of a lever 
I), against it and have a helper hold and press 
against the upper end. Place the drill, C, with 
point against saw and collar, A, B, to be drilled, 
and turn the drill hand over hand by a wrench as 
shown at E. A well tempered drill, supplied 
with a little oil, will soon cut through the plate 
and into the collar far enough to receive the pins. 
In placing the saw it should be turned back 
snugly against the pins before the burr is firmly 
tightened. This will prevent cutting them off in 
case the saw should catch or be bound in the cut. 

HOT MANDRELS. 

Many sawyers are frequently bothered by their 
plates heating at the center from a hot bearing. 
To prevent this, smooth and polish the bearing, 
remove the filling from the box and refill by 
using old type metal in place of poor friction 
babbit that probably has mainly caused the diffi- 
culty. A tine bearing well fitted in this manner, 
and supplied with good, heavy lubricating oil 
will in've no more trouble. 



46 saws. 

Fifing a Fid SajQ^ipi^r. 



In filing a tooth, whether it be for cross-cutting 
or slitting, the filer should run his file perfectly 
fiat and straight and not allow the ends to rock. 
A good square cutting edge cannot be obtained 
unless this be done and it requires practice to do 
it perfectly. The filer should not use larger than 
a ten-inch file for dressing the teeth upon the 
largest plates. If there is a surplus of metal to 
be removed it should be done with the glimmer 
and not with the file. In dressing a tooth the 
feather edge should frequently be brushed off 
with a block or the end of file handle as shown at 
A, Fig. 21. This -will prevent filing too deep 
and causing nnevenness on the points of the 
teeth. A convenient form of gauge for dressing 
the teeth too, is shown at I). If dressed to 
the gauge the same pitch of tooth is always main- 
tained. Case-hardened spots, caused by not 
gnmming properly, cannot be filed and should be 
removed by pressing lightly and quickly upon 
the wheel and removing before there is heat 
enough created to again chill or harden. In 
swaging teeth upon the thicker plates a swage 
should be used having a pitch equal to that of 
the, template shown at E. At B and C is shown 
different w.iys of swaging out the points. The 
point shown at B is far preferable, as it has heavy 
corners to support the width of the cutting edge. 



INDEX. 

Page 

Introductory 3 

Description or tools 7 

Straight edges 7 

Hammers 8 

Anvils _ _•„ _ 10 

Effects of the hammer. 12 

_ .14 

Saw rim-bound .16 

Saw center-bound 18 

Saw blistered 20 

Circular saw kinked . 22 

Long saws 24 

Gumming saws 26 

Balancing plates 28 

Stone gummer 30 

Gumming with st< >ne .32 

Teeth well chambered 34 

Repairing broken teeth 36 

Repairing a fractured ri.ate 38 

Brazing band saws 4o 

Truing up collars 42 

Lug pins 44 

Filing and swaging 4*> 



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